Conventional microbiological laboratory techniques for the identification of a given bacterial sample are relatively complex and occupy considerable time on the part of the laboratory technician. The identification of a pathogenic strain on the throat swab of a patient presenting respiratory symptoms may be taken as an example. The technician must first culture the bacteria in the swab in order to produce enough of the bacterial sample to enable him to carry out the subsequent biochemical tests. Often, particularly in the case of swabs, there will be several bacteria present, not all of them pathogens. Various wellknown laboratory techniques are utilized to isolate and separate the different species one from the other. Generally speaking, each bacterial species can be distinguished from others by its particular reactions to certain known biochemicals. These may be sugars (dextrose, mannitol, lactose, etc.), amino acid preparations (lysine, ornithine, etc.), or preparations of specific substances such as urea, which certain bacteria can "use" for their growth, and others cannot. The procedure is to inoculate or streak the unknown bacteria into test tubes containing the biochemicals, or onto plates or tubes containing a gelled medium in which the biochemical is included. In most cases, particularly with the sugars and the amino acids, a test substance such as methyl red, bromthymal blue or the like would be included, these being substances which change in color with a given change in pH. Because of the relatively large number of test biochemicals which would normally be utilized for identification purposes (anywhere from about twelve to twenty-five or more, depending upon the nature of the symptoms caused, the location of the body from which the sample is taken, etc.), and due to the necessity that the inoculating needle or loop be flame-sterilized between each inoculation, a full program for a single species involving a typical number of biochemicals requires considerable time on the part of the laboratory technician.
After the various biochemicals have been inoculated in their separate test tubes and plates, these are then placed in an incubator or left to incubate at room temperature, in order to allow the bacterial sample to grow in the test medium if it is able to. If growth occurs, the indicator material will change color, and the lab technician is able to record the changes, and then by referring either to his own knowledge or to suitable reference texts, he attempts to establish a particular genus and species for the bacteria under examination. At this stage, human error can creep in. Confusion between the various sugar solutions or among the amino acid solutions occasionally takes place, and the result may be an incorrect identification, resulting in inappropriate treatment of the illness which may eithr prolong it or worsen the condition of the patient.